Reality is…Milk doesn’t come from the back room at the grocery store. And there isn’t a cow living behind the building filling up milk bottles to be sold. So what is this process of preparing the milk? What has to happen before our grocery shelves are filled with a variety of milk options? Walk with me through this and we will see how milk goes from cow to your refrigerator.
Milk production starts with rearing which is essentially raising and caring for the cow and calf. It’s important to feed the calf correctly, providing her with the nourishment necessary to grow. Female calves will be raised until they are full grown and can bred. These full grown heifers will have calves of their own at about two years of age. After the calf is weaned, the cow will continue to lactate for up to a year.
The nourishment needs of a full grown cow varies during the lactation cycles, but producing cows will need plenty of protein in their diet from things like grain, alfalfa and soy meal to produce top quality milk with a high butterfat content. Their daily consumptions of grain and forage can reach 10 to 40 pounds per day. It’s vital that they receive large quantities (12 to 15 gallons) of fresh water per day, too.
I have always wondered how the process of getting the milk out was consistently done. Milk is harvested from the cows 2 to 3 times per day. This can be done by hand, but generally this is done by machines that can milk more than 20 cows all at one time. The process takes roughly five minutes depending on how much milk the cow lets down. This process takes place under sanitary conditions. The teats are cleaned with iodine and wiped with a clean towel. Milker is placed on cow and pulsators are attached to milk the cow. Milk machines mimic the suckling motion of a young calf. After the cow is milked the teats are cleaned again to protect her from infection. After the cow is milked, the raw product is immediately stored in refrigerated bulk tank at 39 degrees Fahrenheit or colder. This is to reduce potential levels of bacteria and ensures a longer shelf life for milk. Milk must remain chilled through the transport process.
Have you ever noticed a large vehicle on the interstate carrying milk? I have and have been curious about the guidelines they have to work by to keep milk fresh. Since milk is collected every day it is vital to transport it correctly and in a timely manner to be sure it gets to the processing site at proper temps. Special tankers that have an insulated stainless steel body allow the milk to remain at a constant cold temperature. When the milk is received at the processing plant it will now go to be tested.
Before the milk can be unloaded at the processing plant it is tested for antibiotic residues and proper temperature. Farm milk samples are tested for butterfat, protein and bacteria. If the milk passes the testing it is pumped into the holding tanks for further processing. If it is contaminated it will be discarded. Milk is stored at the same 45 degree temperatures inside the processing plant. It is usually processed within 24 hours which means it is pasteurized or homogenized and then bottled.
That leaves me wondering what pasteurization and homogenization is? Is it really necessary? Milk arrives to the processing plant in a raw state. This milk can harbor microorganisms and can carry things like: Salmonella, E coli and Listeria. Some of these bacterium have been known to cause foodborne illnesses in humans. Almost all milk in the United States is pasteurized. Louis Pasteur discovered the pasteurization process in the mid 1800’s. This process involves heating the milk. The conditions used for pasteurization depend upon the final product desired. The milk is heated to a certain temperature and cooled without contaminating the product. Lower temperatures are used for refrigerated milk products and higher heat treatments are used for products stored at room temperatures. I’m sure you have seen the many milk options we have. Milk that is homogenized is agitated and filtrated to breakdown the fat molecules preventing separation. The smaller molecules stay suspended in liquid instead of floating to the top. This process came about around 1919 by Augusta Gaulin. Without this process, the fat in 2% milk might separate, rise to the top and not be as appetizing.
Now that the milk is free of potential disease and the proper consistency…we need to properly package it for distribution. I was astounded to research the options. I thought – plastic, paper or maybe glass on rare occasion. But, milk can even be packaged in metal or wood (as long as food safety requirements are met and the package preserves the freshness and flavor).
Well, I am ready for a tall glass of ice cold milk, please join me and enjoy!